Answer:
Centripetal acceleration.
Explanation:
Centripetal acceleration is a property of a body moving in a uniform circular path and it is directed radially towards the center of the circle in which body is rotating.
The force which causes this acceleration is centripetal force which is also directed towards the center of the circle and pulls the body towards its center.
It is calculated through following formula
where v is velocity and r is the radius of the circle.
Answer:
- increasing use of hybrid crops
- altering genes in DNA to create new plants
- developing disease or pest resistant crops
Explanation:
The use of genetic factors to influence the growth of a plant encompasses manipulating the genetic constituent (gene) of such plant.
For example,
- Increasing use of hybrid crops entails mating two pure bred plants based on a gene of interest responsible for a particular trait, to form a hybrid.
- Altering genes in DNA to create new plants is also a genetic factor as it has to with gene modification.
- developing disease or pest resistant crops means that the genetic make up of such plant has been modified to be resistant to pest/disease.
This question is incomplete, the complete question is;
Two plane mirrors intersect at right angles. A laser beam strikes the first of them at a point 11.5 cm from their point of intersection, as shown in the figure.
For what angle of incidence at the first mirror will this ray strike the midpoint of the second mirror (which is 28.0 cmcm long) after reflecting from the first mirror
Answer: angle of incidence is 39.4°
Explanation:
Given that;
two plain mirrors intersect at right angle (90°)
distance d = 11.5 cm
S = 28.0 cm
Now the angle that the reflection ray males with first the mirror equal theta (∅)
so
tan∅ = (S/2) / d
tan∅ = (28/2) / 11.5
tan∅ = 14 / 11.5
tan∅ = 1.2173
∅ = tan⁻¹ (1.2173)
∅ = 50.6°
so angle of incidence = 90° - ∅
= 90° - 50.6°
= 39.4°
Therefore angle of incidence is 39.4°
Answer:
C True. they rise and fall in a circular motion
Explanation:
The movement of water waves in the sea is described by a simple harmonic movement where the water droplets, which are the material particles of the movement oscillate up and down and the wave that is the energy of the movement travels perpendicular to it.
With this let's review the claims
A False
B False
C True.
D False
Answer:
a) P=0.25x10^-7
b) R=B*N2*E
c) N=1.33x10^9 photons
Explanation:
a) the spontaneous emission rate is equal to:
1/tsp=1/3 ms
the stimulated emission rate is equal to:
pst=(N*C*o(v))/V
where
o(v)=((λ^2*A)/(8*π*u^2))g(v)
g(v)=2/(π*deltav)
o(v)=(λ^2)/(4*π*tp*deltav)
Replacing values:
o(v)=0.7^2/(4*π*3*50)=8.3x10^-19 cm^2
the probability is equal to:
P=(1000*3x10^10*8.3x10^-19)/(100)=0.25x10^-7
b) the rate of decay is equal to:
R=B*N2*E, where B is the Einstein´s coefficient and E is the energy system
c) the number of photons is equal to:
N=(1/tsp)*(V/C*o)
Replacing:
N=100/(3*3x10^10*8.3x10^-19)
N=1.33x10^9 photons
